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Search: id:A109123
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| A109123 |
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4(n+1)^2*(n+3)^2*(5n^2+20n+12). |
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+0
1
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| 432, 9472, 64800, 269568, 842800, 2184192, 4953312, 10163200, 19288368, 34387200, 58238752, 94493952, 147841200, 224186368, 330847200, 476762112, 672713392, 931564800, 1268513568, 1701356800, 2250772272, 2940613632
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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Kekule numbers for certain benzenoids.
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REFERENCES
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S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (pp. 311).
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FORMULA
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G.f.=16(27+403z+473z^2-15z^3+14z^4-2z^5)/(1-z)^7.
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MAPLE
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a:=n->4*(n+1)^2*(n+3)^2*(5*n^2+20*n+12): seq(a(n), n=0..28);
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CROSSREFS
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Sequence in context: A069781 A006910 A015229 this_sequence A113921 A047804 A008691
Adjacent sequences: A109120 A109121 A109122 this_sequence A109124 A109125 A109126
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KEYWORD
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nonn
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AUTHOR
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Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 19 2005
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